1. Field of the invention
The present invention relates to the manufacture of composite material components, and in particular to the manufacture of structural components, involving the steps of making a fibrous preform having substantially the shape of the component to be produced, and densifying the preform with a matrix by chemical vapor deposition within the pores of the preform. Such a process is well known in the art, especially in the manufacture of components made from thermostructural composite materials such as carbon-carbon composites and ceramic matrix composites.
2. Prior art
In the manufacture of a thermostructural composite material component, the fibrous preform is generally made from fibrous textures, such as threads, cloth, fiber webs, felts, or laps of fibers. These textures can be wound or arranged in superposed plies. In the latter case, the plies can be bound together by needling or implanted threads.
Once the preform is made, it is generally inserted in an adapted holding tool in order to be densified by chemical vapor deposition. The tool, which is normally made of graphite, serves to maintain the preform in the desired shape while ensuring, if needs be, a compacting of the preform in order to obtain the required volume ratio of fibers (percentage of the preform's apparent volume occupied by the fibers).
When the preform is sufficiently densified to be effectively consolidated, it is withdrawn from the tool before the chemical vapor deposition is continued until the required degree of densification is achieved.
In the above process, some problems that are difficult or expensive to solve are encountered when manufacturing components having complex shapes.
When dealing with large-size components, one known technique involves making different parts of the component separately, and then assembling those parts. The latter can be made simply at the consolidation stage, that is, when not yet completely densified. The components are then obtained by assembling their constituent parts and co-infiltrating the latter to attain the required degree of densification. The coinfiltration of the matrix within these different parts effectively "glues" the latter together, by virtue of their continuity at the interfaces.
This approach requires that the different parts of the component be made separately. Moreover, the bond between the parts in the finished component can turn out to be inadequate.
For small-size components having a complex shape, it is necessary to call on specially designed tools and/or a substantial amount of machining of the densified parts, which considerably increases costs.
It will be noted that the aforementioned techniques do not make it possible to obtain composite material components having an integrated flexible bond, that is, a deformable component.